Add instructions for removing pyc files to docs
Add instructions for removing pyc files to docs

So an issue I hit when following the getting started docs for developers
is that I forgot to remove old pyc files and that can cause
keystone-manage db_sync to throw errors.  I added some extra doc that
explains how to remove these files should this situation be encountered

Change-Id: Ib41c62e99faa7c82f89ab3c5bfa0d740f426829a

dims/keystone,mahak/keystone,klmitch/keystone,klmitch/keystone,mahak/keystone,MaheshIBM/keystone,nuxeh/keystone,dims/keystone,reeshupatel/demo,reeshupatel/demo,idjaw/keystone,rushiagr/keystone,rodrigods/keystone,promptworks/keystone,nuxeh/keystone,jamielennox/keystone,vivekdhayaal/keystone,rushiagr/keystone,MaheshIBM/keystone,rajalokan/keystone,nuxeh/keystone,ging/keystone,promptworks/keystone,ilay09/keystone,openstack/keystone,ajayaa/keystone,jonnary/keystone,dstanek/keystone,rushiagr/keystone,cernops/keystone,roopali8/keystone,jumpstarter-io/keystone,ging/keystone,himanshu-setia/keystone,openstack/keystone,blueboxgroup/keystone,jamielennox/keystone,mahak/keystone,ilay09/keystone,maestro-hybrid-cloud/keystone,reeshupatel/demo,ajayaa/keystone,UTSA-ICS/keystone-kerberos,dstanek/keystone,takeshineshiro/keystone,jumpstarter-io/keystone,cernops/keystone,takeshineshiro/keystone,promptworks/keystone,vivekdhayaal/keystone,dstanek/keystone,rajalokan/keystone,roopali8/keystone,jonnary/keystone,ilay09/keystone,UTSA-ICS/keystone-kerberos,openstack/keystone,rajalokan/keystone,jumpstarter-io/keystone,maestro-hybrid-cloud/keystone,idjaw/keystone,himanshu-setia/keystone,rodrigods/keystone,vivekdhayaal/keystone,blueboxgroup/keystone